Closed Wedge Distal Femoral Osteotomy with a Polyaxial Locking Plate Designed for the Proximal Tibia: Minimum 5-Year Outcomes

Since distal femoral varus osteotomy (DFO) -specific plates had not been available in Japan before 2015, we performed DFO using a plate for tibia. The purpose of this study was to elucidate the efficacy and problems associated with the non-specific plate in DFO. We used NCB-PT plates (Zimmer Inc.) in the upside-down position and the minimum 5-year outcomes were evaluated. The mean preoperative weight bearing line ratio and Japanese Orthopaedic Association score improved from 97.6%±35.8% and 68.0±11.5, respectively, to 44.0%±16.1% and 82.0±7.6, respectively, 1 year postoperatively and to 42.8%±15.7% and 86.0±8.2, respectively, 5 years postoperatively. The flexion range decreased from 149.0°±6.5° to 138.0°±5.7° 1 year postoperatively and to 135.0°±20.9° 5 years postoperatively. Although DFO using the NCB-PT plate provided mid-term benefits, it resulted in a loss of knee flexion, possibly due to excessive coverage of the medial femoral epicondyle.